Bob is right about the need for 12v when on LPG. The spark to light the flame is from the 12v. When you plug in, the batteries automatically come one. Try turning them off at the switch by the door when plug in. You can't get the light to go out.
Ron Tom,
I hate to disagree, but I have found that the batteries are in fact disconnected even if the light stays on. I was scratching my head over that light and decided to track it down; I took the passenger side bed support off (2551) and checked with my volt meter. The light is connected to the
110V AC converter side of the disconnecting solenoid, so that even with the solenoid disconnecting the batteries, the light stays on if plugged into shore power. The light goes out if you disconnect when not plugged in.
You can verify this by turning on the inverter and watching the battery voltage when operating the disconnect switch while plugged into shore power. If the batteries are in need of charge, you will see close to 14v with the batteries connected, and the voltage will drop when you operate the disconnect switch indicating that the batteries are not connected to the system.
When I am connected to shore power, I like to disconnect the batteries after a few days to be sure they are not over charged (probably not necessary with the three stage charger/converter). Since the light stays on, I just listen for the solenoid to operate when pushing the disconnect ("store") switch.
Bob